The present invention relates to a novel strain of bacteria for use in heavy oil degradation, a bacteria mixture, a composition for nurturing heavy oil degrading bacteria, a formulation containing that composition, a method of treating oil components, and building and civil engineering materials containing a substance treated by that method.
Recent years have seen worsening of ocean pollution throughout the world due to heavy oil or crude oil leaks from supertanker accidents, submarine oil field development, etc., and this is one cause of damage to the global environment.
Conventionally, oils, such as heavy oil and crude oil, leaked into the ocean are removed through degradation by microorganisms capable of degrading chiefly hydrocarbons contained in the oils. Specifically, microorganisms which can metabolize and degrade oil components such as saturated hydrocarbons, aromatic hydrocarbons, etc. are screened from the natural world, and the screened microorganisms are isolated and grown, after which a culture solution is prepared for use in degradation of the leaked oil.
In addition, if the microorganisms are provided with nutrients necessary to grow during the degrading and removing process, the microbes are able to exercise their degrading ability to the full. Alternatively, instead of a combination of microorganisms and nutrients, nutrients alone may be added to the object of treatment (e.g. heavy oil), so that the oil is removed through degradation by other kinds of microorganisms having the degrading ability originally present in the vicinity of the object.
For example, bacteria having a hydrocarbon degrading ability are ordinarily present at the seashore. Thus, if the hydrocarbon degrading ability the bacteria inherently possess is activated by providing the bacteria with nutrients, the e.g. heavy oil can be removed through degradation in an ecologically benign manner, which is advantageous for environmental protection.
On the other hand, in order to degrade and remove heavy oil leaked from a supertanker accident, for example, earth and sand with the heavy oil attached thereto are often treated without first being separated from the heavy oil. For example, if heavy oil washed ashore is to be removed through degradation on the seashore, the heavy oil and the earth and sand are generally not separated from each other before degradation and removal processing.
However, when oil, etc. is removed through degradation using microorganisms having the ability to degrade e.g. hydrocarbons in the above conventional manner, growth conditions for the microorganisms must be adjusted by providing various kinds of nutrients.
In other words, in degrading and removing oil components using microorganisms, it is most effective to use living bacteria in a steady period, which is when they show their ability to degrade e.g. hydrocarbons to the fullest. However, in order to use the growing bacteria in the steady period, a culture solution containing expensive nutrients must be prepared, and setting growth conditions precisely requires tedious and time-consuming operations. Specifically, a huge quantity of live bacteria are necessary to remove heavy oil through degradation. Hence, if the required quantity or cost of the nutrients (nutrient salts) per unit volume of the culture solution is high, there arises the problem that costs are too high. Further, too much labor is required to control the growing period.
Also, in order to use live bacteria in a culture solution in degradation, special facilities are required in the storage, shipping, etc. of the culture solution, thus making preparations and operations too complicated.
On the other hand, using microorganisms to degrade and remove heavy oil from earth and sand with heavy oil attached thereto without first separating the heavy oil from the earth and sand also has the problem that further costs are incurred in disposal of the treated earth and sand, which contain degradation products and residual components such as asphalt.
It is an object of the present invention to provide heavy oil degrading bacteria and a heavy oil degrading bacteria mixture which are inexpensively prepared, which simplify degradation and removal operations, and which can be stored and shipped simply, and to provide a nurturing composition for such bacteria, a method of degrading heavy oil using such bacteria, a method of treating oil components using such bacteria, and building and civil engineering materials containing a substance obtained by heavy oil degradation treatment.
In order to achieve the above object, the inventors of the present invention conducted an assiduous study, and completed the present invention when they discovered that the above object can be achieved by using strains of bacteria collected from seawater by means of screening, and a mixture thereof.
Novel strains of bacteria according to the present invention which have a heavy oil degrading ability and can achieve the above object are FERMBP-7046, a strain belonging to the genus Acinetobacter; FERMBP-7049, a strain belonging to the genus Acinetobacter; FERMBP-7047, a strain belonging to the genus Pseudomonas; FERMBP-7048, a strain belonging to the genus Alcaligenes; FERMBP-7050, a strain belonging to the genus Flavobacterium; FERMBP-7051, a strain belonging to the genus Flavobacterium; FERMBP-7052, a strain belonging to the genus Flavobacterium; and FERMBP-7053, a strain belonging to the genus Moraxella.
A bacteria mixture according to the present invention which can achieve the above object is a bacteria mixture including at least one kind of bacteria having a heavy oil degrading ability selected from the group consisting of: FERMBP-7046, a strain of Acinetobacter; FERMBP-7049, a strain of Acinetobacter; FERMBP-7047, a strain of Pseudomonas; FERMBP-7048, a strain of Alcaligenes; FERMBP-7050, a strain of Flavobacterium; FERMBP-7051, a strain of Flavobacterium; FERMBP-7052, a strain of Flavobacterium; and FERMBP-7053, a strain of Moraxella.
The foregoing bacteria or bacteria mixture was discovered when bacteria were isolated from seawater in order to discover a strain having a hydrocarbon degrading ability in nutrient-poor conditions as close as possible to those in the natural world. Thus, the above bacteria or bacteria mixture can be readily grown on inexpensive nutrition sources and degrade hydrocarbon efficiently. Accordingly, leaked oil components, for example, can be easily and efficiently removed through degradation at a low cost by using the foregoing bacteria or bacteria mixture.
In particular, the above bacteria mixture shows a better ability to degrade oil components than when each of the foregoing kinds of bacteria is used alone, and for this reason, heavy oil can be removed through degradation more efficiently by using the above bacteria mixture.
In addition, degradation of heavy oil can be further promoted when the bacteria mixture also includes at least one of FERMBP-7050, a strain of Flavobacterium; FERMBP-7051, a strain of Flavobacterium; FERMBP-7052, a strain of Flavobacterium; and FERMBP-7053, a strain of Moraxella.
Additional objects, features, and strengths of the present invention will be made clear by the description below. Further, the advantages of the present invention will be evident from the following explanation in reference to the drawings.